A famous story surrounding the 1930 version of “All Quiet on the Western Front” says that Zazu Pitts was replaced as Lew Ayres’ mother in the version released in the United States because preview audiences laughed at her — aside from her stunning dramatic performance in “Greed,” Pitts was known as a leading comic actress — but that Pitts appeared in the silent version released overseas. This turns out not to be true, as you can see for yourself at Film Forum, which today only is showing the superb silent version, which actually has a synchronized music track and a few words of French dialogue not heard in the much stiffer talkie version Universal released domestically. Of all the Oscar winning best pictures, “All Quiet” is the only one that apparently no longer exists in its original domestic version, which ran around 140 minutes. Two reels were cut after its premiere, and it was further whittled in 1939, when voice-over narration was added linking the World War I story to the just-starring World War II were added. Universal tinkered with it some more for a 1950 reissue, adding music that upset director Lewis Milestone, especially in the famous final scene of Ayres being shot by a sniper as he reaches for a butterfly. The music-less talkie version was restored to not quite its original length by the Library of Congress a decade ago, but it turns out the longer silent version restored around the same time is far superior. As Film Forum’s Bruce Goldstein put it, it’s longer “longer, with more shots, more fluid camera movements, smoother editing transitions, more character details…putting what is already a camera legend in a fresh, more complete light.” Don’t miss this great movie — it’s flabbergasting that Ayres was not Oscar-nominated as a young German recruit — today only at 3:30, 6:50 and 9:50 p.m. As for Miss Pitts, she does turn up as Ayres’ mother after all — in a theatrical trailer for “All Quiet” that will precede the feature. In the movie itself, the role is played by British character actress Beryl Mercer, who had her juiciest screen that same year, 1930, in another World War I story, “Seven Days Leave” (an adapation of J.M. Barrie’s short story “The Old Lady Shows Her Medals”) as Dougboy Gary Cooper’s mom. The following year, she had her most famous part, as Cagney’s mother in “The Public Enemy.” Mercer closed out her career in 1939 by playing Queen VIctoria in two Fox movies, “The Story of Alexander Graham Bell” and the Shirley Temple vehicle “The Little Princess.”